MX2011008699A

MX2011008699A - Interfacial refraction accommodating lens (iral).

Info

Publication number: MX2011008699A
Application number: MX2011008699A
Authority: MX
Inventors: Khalid Mentak; Beda Steinacher; Philipp Stucklin; Hans Fluckiger
Original assignee: Adoptics Ag
Priority date: 2009-02-18
Filing date: 2010-02-18
Publication date: 2011-11-29
Also published as: US20090264998A1; KR20110127706A; BRPI1008687A2; EP2323590A1; US8034106B2; JP2012517889A; AU2010223018A1; WO2010104654A1; CN102316825A

Abstract

This invention relates to intraocular lenses. More particularly, this invention relates to intraocular lenses that have the ability to alter the light refractive power in response to changes in the tension of the ciliary muscle or ciliary body of the eye or any other accommodative forces. Lenses of this invention are generally referred to as interfacial, i.e., lens properties being defined as the interface of two liquids having different refractive indices, refractive accommodating lenses (IRAL).

Description

LENS OF ACCOMMODATION BY INTERFACE REFRACTION CROSS REFERENCE TO RELATED REQUESTS This request is a continuation in part of the application for E.U.A. pending 12 / 025,512 filed on February 4, 2008, which claims priority of the provisional applications of E.U.A. with serial numbers 60 / 887,933 and 60 / 887,928 both filed on February 2, 2007, the description of all of which is incorporated herein by reference (including any references incorporated by reference in either or both of the provisional applications) in their entirety .

FIELD OF THE INVENTION This invention relates to infraocular lenses. More particularly, this invention relates to infraocular lenses that have the ability to alter the refractive power of light in response to changes in the tension of the ciliary muscle or ciliary body of the eye or any other accommodation forces. The lenses of this invention are generally referred to as accommodation lenses.

BACKGROUND OF THE INVENTION The natural lens of the human eye is a transparent crystalline body, which is contained within a capsular bag located behind the iris and in front of the vitreous cavity in a region known as the posterior chamber. The capsular bag is attached on all sides by fibers, called zonules, to a muscular ciliary body. On its back, the vitreous cavity, which is filled with a gel, also includes the retina, on which the rays of light that pass through the lens are focused. The contraction and relaxation of the ciliary body changes the shape of the bag and the natural crystalline lens in it, thus allowing the eye to focus the rays of light that originate from objects at various distances on the retina.

Cataracts occur when the natural lens of the eye or its surrounding transparent membrane becomes cloudy and obstructs the passage of light resulting in varying degrees of vision impairment. To correct this condition in a patient, a surgical procedure is performed in which the cloudy natural lens, or cataract, is removed and replaced by an artificial intraocular lens. During cataract surgery, the anterior portion of the capsular bag is removed along with the cataract, and the posterior portion of the capsular bag, called the posterior capsule, is sometimes left intact to serve as a support site for implanting the intraocular lens. (IOL). Said conventional lOLs, however, have the disadvantage that they have a fixed refractive power and therefore are unable to change their focus in response to the patient's changing focal distance needs, such as reading or computer work.

Several types of intraocular lenses that have the ability to alter their refractive power have been suggested in an effort to double the performance of the natural lens within the eye. Such intraocular accommodating lenses, as are known in the art, have a variety of designs to allow the patient to focus, and therefore clearly see, objects located at a plurality of distances. Examples can be found in publications such as the US patent. No. 4,254,509; patent of E.U.A. No. 4,932,966; patent of E.U.A. No. 6,299,641; patent of E.U.A. No. 6,406,494, and US patent. No. 7,261, 737.

The patent of E.U.A. No. 5,443,506 of Garabet describes an infraocular lens of variable focus that alters the medium between the two surfaces of the lens to alter its accommodation. The lens of the '506 patent has continuous flow loops that engage a channel in a first portion of the intraocular lens. The continuous flow loops, in addition to providing a channel, provide the means by which the intraocular lens is placed and held in the eye. In one embodiment, the continuous flow loop (s) comprises the haptic of the lens, that is, the support structures of the lens body, which, in turn, move a charged solution to an optical zone between the surfaces of the solid lens to change the focus of the lens.

The patent of E.U.A. No. 5,489,302 describes an intraocular accommodating lens for implantation in the posterior chamber of the eye. This lens it comprises a short rigid tubular frame and transparent and elastic membrane joined thereto in its bases. The frame and the membranes confine a sealed space filled with gas. The frame includes flexible regions joined by haptics to the posterior capsule. By stretching the capsule through the ciliary muscles of the eye, the flexible regions are separated, thus increasing the volume and decreasing the pressure within the sealed space. This changes the curvature of the membranes and consequently the refractive power of the lens.

The patent of E.U.A. No. 6,117,171 describes an intraocular accommodating lens that is contained within a rigid encapsulating shell to render it substantially insensitive to changes in the intraocular environment. The lens is adapted to be implanted within the posterior capsule and comprises a flexible transparent membrane, which divides the interior of the intraocular lens into separate front and top spaces, each filled with a fluid having a different refractive index. The periphery of the posterior space is attached to the haptic, which in turn is attached to the posterior capsule. By the stretching of the capsule by the ciliary muscles of the eye, the haptic and therefore this periphery is separated in a crooked manner to increase the volume of posterior space and change the pressure differences between the spaces. As a result, the curvature of the membrane and consequently the refractive power of the lens changes.

Another approach to varying the focus of an IOL is to form a conventional hard intraocular lens with a flexible outer surface from a material such as silicone. Water is injected between the conventional hard portion of the lens and the flexible outer surface of the lens. The water will stretch the outer flexible layer to change the radius of curvature of the intraocular lens and thereby change the accommodation of the lens. A disadvantage of this approach is that the fluid source, a fluid pump and a flow control valve must all be provided within close proximity to the lens. Since the area around the lens of the eye is very confined, most of the fluid injection components have to be provided in the lens itself. In addition, a source of energy must be provided to pump the fluid. Since there is no mechanical force generated in the eye that is strong enough to pump the fluid, an external energy supply is required to operate the pump. Said external power supply is usually implemented using a battery that has a limited life cycle.

An additional approach that has been used to vary the accommodation of the IOL is the coating of the conventional IOL with a liquid crystal material. A voltage source is applied to the crystal material to polarize the crystals. Once the crystals are polarized, the refractive index of the crystalline material changes, thus changing the accommodation of the IOL. A major advantage of this type of system is the relatively large amount of energy that is required to polarize the liquid crystal material, in the order of 25 volts. Since there is no known way to generate that level of voltage within the body, an external energy source, such as a battery, is therefore necessary.

Some conventional accommodation IOLs are based on a solid curved surface to provide refraction. As such, the force required for a significant enough curvature change to induce an increase in diopters and accommodation power is much greater than that provided by the ciliary muscles especially in long-term lenses. Other lOLs of accommodation involve a displacement of the entire IOL along the optical axis to create accommodation. This not only requires a relatively larger force but also fails to provide larger diopter changes due to the lack of space in the anterior chamber.

The attempts described above and other prior attempts to provide an intraocular lens with variable accommodation are generally complex systems. These complex systems are expensive and difficult to work with and often impractical to increase in a human eye. Therefore, the current accommodation lenses provide little accommodation power (approximately 1 to 2.5 diopter "D"). For the purposes of this technique, it is understood that the multifocal lens is not necessarily an accommodation lens, cf., US 7, 229, 475. A true accommodation lens that simulates very closely the accommodation of the natural lens must have at least about 4D, preferably at least about 6D or more of the accommodation power. In addition, multifocal lOLs provide a limited number of distances at which vision is adequate. In contrast, the lOLs of accommodation allow the patient to achieve good vision at any distance to the provide a continuum of the focal lengths of the lens to meet the needs of the user. Therefore, there is a need for a simple IOL with higher levels of accommodation power based only on the force provided by the human eye for operation BRIEF DESCRIPTION OF THE INVENTION The present invention addresses the drawbacks of prior art lenses and lens assemblies through the use of a novel refraction system based on the naturally created interface between the first and second immiscible fluids or liquids (sometimes referred to as "and" II "). A significant change in refractive power can be achieved in a practice of this invention with application of minute forces and changes of force, eg, by the ciliary muscle or ciliary body, without the need for movement of the IOL to through the optical axis.

An accommodation IOL of the present invention generally comprises a lenticular chamber in which two immiscible liquids are in contact with one another forming a meniscus. The interface between the two liquids provides the refractive surface that diverts light to a focal point in the retina. The curvature of the meniscus and therefore the focus of the lens is changed by applying pressure on the periphery of the lens generally by means of the lens haptics. A very small force, eg, by contraction of the ciliary muscle applied to the haptic, is required to cause a significant change in the curvature of the meniscus, which in turn changes the lens diopter to provide focus on objects at various distances. The force is transmitted from the ciliary muscles to the meniscus through the haptic. The haptic can be formed in various configurations including C-loop, modified C-loop, frame, disc-type, plate, etc.

In a preferred practice of this invention, the haptics themselves are at least partially hollow having internal haptic chambers that contain fluid, the haptic chambers are in fluid communication with a lenticular chamber or lens body in such a way that the displacement of the haptic, e.g., subsequently, causes some fluid I or II to flow into the body of the lens and improve, increase or amplify the accommodation obtained. In this aspect of the invention, either or both of the usually transparent back or front walls defining the lenticular chamber are flexible or stretchable in such a way that they can be displaced by one or the other of the fluids. In preferred practice, only the wall of the posterior lenticular chamber is flexible or stretchable, allowing it to be subsequently displaced when the fluid from the haptic chamber flows into the haptic chamber. In this embodiment of the invention, the hollow lens haptic are preferably rectangular in shape they are preferably two in number, and are arranged on opposite sides of the optical body.

A variety of liquids can be used for this invention. The most important parameters are clarity, surface energy, density, viscosity in refractive index. Virtually any combination of liquid can be used. The accommodation power for a variety of fluid combinations was calculated based on the change in meniscus curvature. The following table 1 summarizes some of those results. In a preferred practice of this invention, the densities of the respective liquids are substantially the same.

In another embodiment of this invention, the liquids are only optionally immiscible (ie, they can be miscible). In that embodiment, liquids would be separated by an optically acceptable membrane or film. The film would maintain separate miscible fluids or liquids and confine fluids I and II to produce a variable diopter change in accordance with the invention. The film or membrane is applied to the edge of the discs in such a way that the mixing of miscible liquids having different refractive indices (Rl) is avoided. In a preferred practice, liquids (or more generally "fluids" since one of the liquids can be air) has substantially the same densities. By "substantially the same densities" is meant densities of a similarity such that fluids or liquids can be contained within an elongated, vertically disposed optical chamber, and are immiscible as described herein, fluid (s), or liquid ( s), have little or no tendency to "settle" at the bottom of the chamber (or collect at the bottom of the chamber) due to gravitational forces and therefore maintain a separate relationship, vertically disposed one with respect to the other when the user is watching horizontally or at a distance.

TABLE 1 The advantages of the IOL method of accommodation of the present invention, not previously known in the art, are: 1. Stable refraction since the interface between two immiscible liquids is naturally stable due to considerations of free energy. 2. The interface can be moved with tiny forces. This allows a change of curvature with minimal forces of the ciliary muscles and therefore significantly larger diopter changes. 3. The design is relatively simple and similar to conventional lOLs. Essentially, square edges can be incorporated into the design to avoid opaqueness of the posterior capsule (PCO).

A lens of this invention provides true accommodation and substantially increased lens diopter changes hitherto not known in the art.

Therefore, in one aspect the present invention is a method for obtaining diopter changes, by means of an accommodation IOL, of at least two diopters, preferably at least four diopters, and most preferably at least six diopters ( up to 10 diopters or more) in response to a physiological demand from the IOL patient implanted for that change. In a very real sense, the present method of accommodating and accommodating IOL apparatus closely simulates the focus setting of the lens and response of a young, healthy, pre-cataract eye.

The term "capsular unit", as used in the present description and claims, refers to the lower capsule, in the formulas, and the ciliary bodies, are interconnected and act in unison, forming in accordance with the present invention, a type of wire whose variable tension provides the axial force applied to and utilized by the lens assembly of the present invention to achieve accommodation.

A lens of the present invention is a substitute for a natural lens after it is removed from the eye, not only by allowing the eye to see better (or in some way) after the assembly is implanted, but also by allowing it to be accommodated. and therefore focus objects located in a continuum of distances. To achieve accommodation, the Assembly is designed to be fixed in the posterior chamber, in the capsular bag or sulcus, with the elastic body resting axially on the upper capsule or sulcus.

The lens assembly of the present invention utilizes the natural compression and relaxation of the capsular unit or sulcus to impart an axial force on the elastic body to cause it to act as a lens whose radius of curvature and hence the refractive power provide, I varied depending on the magnitude of the force. In this way, the lens assembly cooperates with the eye's natural operation to accommodate and allow the eye to see objects more clearly at different distances.

The haptic element of the assembly according to the present invention can adopt any of a variety of designs known in the art, v. Gr, it can be curved or it can be in the form of a plate. In addition, the haptic element may be completely transparent or opaque. The haptic element of the lens assembly according to the present invention can be made from a variety of possible rigid materials suitable for invasive medical use and known in the art to be used in haptic formation. As noted above, in a preferred embodiment, the haptic is at least partially hollow, containing one of the fluids, and being fluidly coupled via a channel to the lenticular chamber or lens body.

The advantages provided by the accommodation lens assembly of the present invention are many. In lens assembly you do not need conform to the size or shape of the capsule, and therefore it is free to adopt a variety of larger designs. In addition, the capsule is sometimes damaged during surgery to remove the natural lens, but the lens assembly of the present invention does not require the capsule to be completely intact in the form of a bag but simply to remain reliably connected as part of the unit. capsular Another advantage that arises from the lens assembly that is placed outside the posterior capsule is that it remains unaffected by the permanent and unpredictable restriction that the capsule inevitably suffers due to scarring after surgery for lens removal, usually referred to as fibrosis. capsular that occurs in all patients and to varying degrees. For conventional accommodation lOLs that rely on the forward movement of the lens optics to provide accommodation, capsular fibrosis immobilizes the lOLs and limits the forward movement of the optic causing an inconsistent clinical output and a limited range of accommodation. The IOL of the present invention does not require the optics to move forward.

In addition, in one embodiment, the lens of this invention is collapsible. In this embodiment, the lens comprises foldable, optically acceptable materials. Therefore, all the advantages of a folding IOL known to one skilled in the art are provided.

In addition to the above, the lens assembly of the present invention offers advantages such as simple construction and low cost. In The lens assembly of the present invention also provides the ability to accommodate within a wide range of refractive power, including the full range provided by the natural eye and much more if necessary in the case of other eye diseases such as related macular degeneration. with age (AMD). Also, the lens assembly provides means to vary its sensitivity in response to the force applied by the capsular unit. In addition, the lens assembly is similar in design to conventional monofocal lOLs and can be implanted using surgical instruments and existing surgical techniques. No training or special surgery training is required.

BRIEF DESCRIPTION OF THE DRAWINGS In order to understand the invention and see how it can be carried out in practice, the preferred embodiments will now be described by way of non-limiting examples with reference to the accompanying drawings in which: Figure 1 is a flow diagram showing the interaction between the accommodation IOL and an optical sensory mechanism of the patient to provide improved visual acuity; Figure 2 is a front view of an interfacial refraction accommodation lens or lens assembly (IRAL) in accordance with the present invention; Figure 3 is a cross-sectional view of the IRAL shown in Figure 2; Y Figure 4 is a perspective view of a second embodiment of the present invention in which the direction of the application of force to the haptic by the ciliary muscle is illustrated by arrows (11). The accommodation lens of figure 4 also has a haptic configuration different from the lens of figures 1 and 2.

Figure 5 is a perspective view of a modality of the piezoelectric or electrical accommodation lens of the present invention.

Figures 6A-6B show a further embodiment of the present invention in which Figure 6A shows an IOL of the invention in the accommodated state and Figure 6B shows the same IOL as shown in Figure 6A in a non-accommodated state.

Figures 7A-7B show the accommodated and non-accommodated states, a further version of an IOL of this invention.

Figure 8 shows a third accommodation IOL of this invention in cross section.

Figure 9 is an IOL as shown in Figure 8 in a non-accommodated state, ie the haptic are not disposed subsequently.

Fig. 10 shows the lens of Fig. 9 in cross section along line 10-10 of Fig. 9, the direction of view being to the right (subsequently).

Figures 1 1 and 13 illustrate in side view, a top view, and in section along line 13-13 of Figure 12, respectively, an additional accommodation IOL of the present invention.

Figure 14 shows the IOL of Figure 13 in a state of accommodation, the haptic being slightly bent, flattened or moved in the direction of the arrows towards the bottom of the figure.

Figure 15 shows an implantation site of an IOL of the present invention, the IOL being in an accommodated state Figure 16 shows the IOL of Figure 15, as it is implanted, in a non-accommodated state.

Figures 17, 18 and 19 show in side view, in top view and in section, respectively, the additional embodiment of an IOL of this invention.

Figures 20 and 21 show an implantation site of the IOL of Figures 17-19 in an accommodated and non-accommodated state, respectively.

Figures 22, 23 and 24 show a further embodiment of the present invention, in side view, top view and section taken along line 24-24 of Figure 23.

Figures 25-26 and 27A-27D show a further embodiment of the present invention in which the fluid chambers of the lens haptics are coupled to the lens body and which upon moving subsequently (or previously) change the focus of the lens .

Figure 28 shows the change in power of the IRAL lens in response to the forces exerted on the haptic simulating the process of natural accommodation in the eye.

DETAILED DESCRIPTION OF THE INVENTION The basic principles of accommodation lenses are, of course, well known to one skilled in the art. These principles are illustrated in Figures 1 and 2 (and associated description in column 4, line 20 to line 52) of the U.S. patent. 5,489,302 whose description is specifically incorporated herein by reference.

Generally, in one aspect, this invention is an implantable interfacial refractive ophthalmic lens (IRAL) assembly or apparatus that adjusts its focal length in response to changing the physiological needs of the wearer of said lens (e.g., a patient in which the lens has been implanted). The lens comprises a flexible optical camera, lens or optical body and cooperative haptic. The optical chamber is defined by discs or elastic or stretchable walls that are substantially parallel, visually transparent, generally circular, which are flexibly coupled at their edges and separated to define a closed fluid chamber. The fluid chamber flows a first and second liquid, liquids having different refractive indices (the difference being ARI) and, in one embodiment, being immiscible and preferably of substantially the same densities as defining a spherical or lenticular interface changeable or changing between them. The haptic is coupled to the edge of the optical chamber and to the fluid chamber so that the application of force to the haptic deforms the fluid chamber, displaces the fluid to the optical chamber and therefore changes the sphericity of the liquid interface. Therefore, the focal length of the lens assembly changes in response to the application of force to the haptic to change the user's visual focus. Under relaxation of the force of the ciliary muscle applied to the haptic, the haptic, which have a natural deviation in resisting the applied force, return to its configuration or pre-force application arrangement, the lens diopter therefore declining by the change in the form of I, II, fluid interface.

In one embodiment, the fluids are optionally immiscible and are separated by a flexible, visually transparent membrane, which is sealed at the edge of the disc (s) to define a flexible fluid chamber and which prevents fluids from mixing.

This invention also includes a method of correcting visual activity by using an accommodation IRAL, the method comprising the steps of: replacing a defective natural lens of an eye of a patient in need of such replacement by an accommodation IRAL; allow the IRAL to accommodate the needs of the patient to change the focal point of the eye, eg, the retinal focus, by changing the strength of diopters and therefore the focal point of the IRAL where the change in strength of the diopters of the IRAL is at least two diopters; and where the IRAL uses liquids that have different indexes of refraction to define change the force of diopters and therefore the interface.

Figure 1 is a flowchart showing the optomechanical principle that allows an accommodation lens, e.g., an accommodation IOL, to interact with physiological optical signals to provide near and better visual acuity to a lens user. In short, the brain instructs the muscular ciliary body (eye muscle) to contract. This muscle contraction applies a sudden force, usually subsequently directed to the haptic lens (described below) by zonular fibers. That force applied to the haptic causes the optical power of the accommodation lens to shift thereby focusing the incoming light on the retina with greater accuracy and with increased clarity. The box 100 generally shows the haptic and coupled optomechanical functions of an accommodating or accommodating IOL, such as a lens of this invention, in that process. The haptic focuses the IOL in the focal area of the focal axis of the eye and receives and transmits strength from the ciliary muscle to the optical chamber or lens body (described in more detail below). The haptic may be in direct contact with the eye muscle if the IOL of accommodation is implanted in the sulcus. The optomechanics of an accommodation IOL of the invention then converts the strength of the ciliary muscle into diopter lens changes.

Figure 2 is a front view of an interfacial refractive accommodation lens (IRAL) of the present invention. In figure 2 it is shown a lens assembly 10 comprising an optical camera or lens body 12 and haptic 14. It will be understood that the haptic 14 shown in Figure 2 is only a possible haptic configuration, with many others easily occurring to an expert skilled in the art. the technique in view of this description. Also shown within the optical chamber 12 by a dotted circle 16, 16 'is the position of the refractive surface (i.e., the interface between the two fluids) in response to the force exerted by the ciliary muscles.

Figure 3 is a cross-sectional view of the IRAL shown in Figure 2, showing the relationship between the deformation of the haptic or displacement angle 15, 15 'and the change in the interfacial curvature radius 16, 16' achieved by changes in the angle of haptic deformation very small. The change in the shape of the interface 16 shown in Figure 2 illustrates the increase in the radius of curvature of the refractive surface under changes in haptic pressure. Changes in haptic pressure are obtained by changes in the deformation of the haptic, in turn, result from increased pressure of the ciliary muscle or capsular bag. As shown, the radius of curvature of the inner wrap, 16, 16 'changes in response to changes in the angle of deformation of the haptic. The change in radius of curvature together with liquids I and II (which have refractive index characteristics detailed below) creates substantial diopter changes for very small ciliary muscle movements. The changes in diopters by change of degree in the angle of deformation for several liquids I and II are shown in table 1 above.

Clearly, the invention provides diopter changes that are substantially in excess of anything described in the prior art. Therefore, for example, the diopter changes (and the accommodation as described above) in the range of four diopters, preferably six diopters, and most preferably about 7.5 diopters or more are obtained in a practice of this invention.

Figure 4 is a perspective view of another embodiment of the present invention in which the direction of application of force, by a ciliary muscle, is shown on arrow 11. Haptic 14 is of an additional partial loop variation consistent with the teachings of this invention. Additional embodiments of the optical chamber, fluid chamber or lens body 12 are described below.

Figure 5 illustrates an electrical or piezoelectric design or approach to the present invention. As indicated, a circular transducer or haptic element 40 is coupled or connected by the connecting or coupling element 42 to the fluid chamber 44. According to this approach, the movement of the transducer-haptic element 40 by the ciliary muscle of the The user causes an electrical signal to be transmitted, via a conductive element 42, to the fluid chamber 44. Accommodation in the eye is induced by contraction of the ciliary muscles (not shown) and capsular bag (not shown). A method of this invention involves a transducing element 40 which detects the strength of the ciliary muscle and generates an electrical current or voltage through the lens chamber 44. The electrical voltage induces a change in surface energy along the surface of the chamber 44 which in turn causes an inclination of the curvature of the interface between the two liquids. In one aspect, then, the invention is an accommodation IOL wherein the change in interface curvature is directly induced by the electrical impulse generated by the ciliary muscle during contraction. In this modality, the haptic is made of a conductive material. A conductive element could also be embedded in the haptic.

A transducer capable of converting the movement of the ciliary muscle or capsular bag into an electrical signal is used to effectively change the shape of the meniscus and allow accommodation. The transducer can be a piezoelectric device, a force sensor, an actuator or any other element capable of converting a force into an electrical signal. The haptic may be made of a force sensing element. The haptic can be deformed in various configurations including C-loop, modified C-loop, square, disc-type, plate, etc.

The materials chosen to practice this invention will be readily apparent to one skilled in the art. In one embodiment, the haptic materials may include PMMA, PVDF, PP, or other polymers. The materials of the optical chamber 12 may include hydrophobic acrylic polymers or copolymers (HAC), hydrophilic acrylic polymers or copolymers, silicone polymers or copolymers (PDMS) or other polymers. Preferred polymers include PDMS or HAC (12 and 16 are made from the same material).

As indicated, the relationship between the refractive indices of liquids I and II is required to obtain the advantages of the present invention.

Reference will now be made to Figures 6A-14 in which several additional embodiments of this invention are shown. In Figures 6A-6B, the anterior side of the implant, lens body or lens assembly 20 is generally on the left; the posterior 22, usually to the right. The lens body or optical chamber generally comprises the disks 24, 26 which are flexibly coupled to their edges 28. As shown, the flexible coupler or side wall 28 is compressible and provides an annular connection between the disks 24, 26, coupler 28 .

Since the disks 24, 26 are separated along the focal axis of the eye (when implanted), a closed fluid chamber 30 is defined. Chamber 30 contains immiscible liquids 32, 34 having different refractive indices in accordance with this invention. Generally, the higher refractive index liquid will subsequently be disposed in the lens body 34, with the lower refractive index liquid 32 being anterior, although the opposite arrangement can be used in some embodiments.

Due to the immiscible liquids 32, 34, a spherical curve interface 36 is formed. At its perimeter, the interface has a fixed contact angle 40A at the interface to the implant side wall 28. The curvature of this liquid interface depends on the properties (surface tensions) of the liquids and the implant material. Corresponds to a minimum of energy. The strength of the eye muscle is transmitted to the implant by the haptic schematically shown by the arrows 42, the thicker arrow indicating a greater force. This applied force deforms a side wall 28. Due to the fixed contact angle 40, a change in the inclination of the side wall will change the radius of the liquid interface 36 (a minimum of energy is achieved). A change in radius will lead to a change in optical power, i.e. diopter rate of device 10. In this way the focal length of the IOL will change to provide a better focus of incident light on the retina (not shown).

In FIGS. 7A-7B, a variation is shown in which the force of the eye muscle is transmitted to the implant by the haptic to a displaceable annular side wall 50. The applied force shown by the arrows 52 pushes the liquid interface as far as possible. length of the variable curved side wall 50. This is done by deforming the hinge-like structure 56, which is integrated into an implant. One can think of other possible mechanical solutions to achieve the movement of the liquid interface along the structured side wall 50. As the inclination of the side wall 54 changes, the liquid interface will adapt its curvature to achieve the angle of fixed contact. This corresponds to a minimum of energy. A change in the radius will lead to a change in the optical power of the device.

Due to the immiscible liquids, a spherical curved interface 36 is formed. At its perimeter 54, the interface has a fixed contact angle to a movable ring structure within the implant 10. The curvature of this liquid interface depends on the properties (surface tension) of the liquids and the implant material. The strength of the eye muscle is transmitted to the implant by the haptic. Figures 8, 9 and 10 illustrate a further embodiment of the invention. The haptic 80 in this embodiment is internally coupled to a movable inner ring 81. The force applied on the arrows 82 move the ring structure 81 within the implant. The structure of the movable ring could be made of different materials (e.g., having a high stiffness) than the implant. As the ring structure is swept through the liquid interface, a certain radius of the liquid interface will be formed corresponding to a minimum of energy. The change in radius will therefore lead to a change in the optical power of the implant.

Figures 1-14 illustrate a lens in which both the static power and the accommodation power are also generated by the interface between the two liquids. The implant is designed in such a way that the haptics are in contact with the sulcus. Designs where the implant sits in the lens bag are also feasible. The design shows four haptics 90, which are in contact with the sulcus. You can think of designs with less or more haptic. In the accommodated state, the contracted ciliary muscle pushes the haptic in the direction of the vitreous body. This will lead to a movement of the ring inside the implant in the opposite direction. The liquid interface will form a certain radius corresponding to a minimum of energy (depending on the design of the ring structure and the materials involved). Arrows 98 generally show the direction of change in the deformation of the haptics 90 to achieve the accommodated state or of accommodation. In Figure 14, the curvature of the liquid interface is increased compared to the non-accommodated state 96 (figures 11, 12 and 13) and the optical power of the implant is increased.

Calculation of lens parameters The results are obtained using the following formula (paraxial approximation) A D I Radius of the liquid interface = - Static power The results are obtained using the following formulas (paraxial approximation) Radius of the liquid interface in the non-accommodated state: Radius of the liquid interface in the accommodated state: ARI R2 = Static power + accommodation Angle of deformation of the side wall Angle of deformation = sine of the arch Using the Taylor approximation, this formula can Simplified additionally to: in ", / n a ^ nma ^ n DLenfe · 180 ° accommodation / Angu / o of deformation 2 ·? / · 1000 p where the tooth is in mm and the accommodation in D.

TABLE 2 TABLE 3 ARI = 0.1 ARI = 0.23 Accommodation [D] Angle of deformation Angle of deformation of the side wall [°] of the side wall [°] 6 14.4 4.7 10 27.3 7.9 20 is not possible 16.3 TABLE 4 TABLE 5 TABLE 6 TABLE 7 Figures 15 and 16 generally show the site of the implant in the eye where a lens of this invention would be located. Previous is on the left while back is on the right. The incident light enters from the left and has to be focused on the retina (not shown). Figure 15 shows, eg, a lens of Figures 9-14 with the contracted ciliary muscle 1 10 applying force to the haptics 90-to deform the surfaces of the immiscible liquids in the lens body 10 for the change of optical characteristics of the lens, that is, to accommodate the optical need of the patient receiving the implant. The structures of the eye, sulcus 1 12, vitreous body 114, cornea 1 16, iris 1 18, collapsed lens bag 120 and zonules 122 are shown. Figure 16 shows the same implant site and IOL with relaxed ciliary muscle (a state not accommodated).

Figures 17-19 show a variation in which an anterior uniconvex lens 140 is used. All other structural elements are the same.

Figures 20-21 show the lenses of Figures 17-19 as they are implanted.

Figures 22-24 show an equiconvex or biconvex IOL design 160 of this invention. An implantation view would be similar to that shown in Figures 15 and 16.

Figures 25-26, 27A-27D and Table A show a preferred embodiment of this invention in which one or the other fluids I, II are contained within the hollow lens haptic and are displaced within the optical body, v. gr., by contraction of the ciliary muscle. The lenses shown generally look towards the bottom of the page. Figure 25 shows in section a non-accommodated lens 200 comprising an optical camera or lens body 202 defined by transparent anterior and posterior lens walls 204 and 206. The hydrophobic and hydrophilic liquids 208, 210 are contained within the optical chamber 202, and define an interface 212 in accordance with the invention. The haptic 214 is at least partially hollow, defining haptic chambers 216 which is fluidly coupled by a channel 218 to the optical chamber 202.

Figure 26 shows the lens 200 of Figure 25 in an accommodated state where the posterior displacement of the haptic 214 obtains accommodation. As shown, the rear lens wall 206 is flexible allowing subsequent bulging which allows for increased accommodation by increased change in curvature defined by interface 212. Arrows 218 show the direction of haptic movement while arrows 220 show the direction of fluid flow in response to displacement of the haptic. Although not shown, fluid flow occurs in the reverse direction (ie, towards the haptic chamber 216) when the haptic in Figure 26 is allowed to return to the configuration shown in Figure 25. Thus, accommodation and relaxation of the accommodation are obtained.

Figures 27A-27D and Table A illustrate in partial plan and partial section additional embodiments of the lenses shown in Figures 25 and 26. As shown, rectangular hollow optics are used, arranged in the opposite direction. Another lens / haptic body configuration will occur to one skilled in the art.

TABLE A Accommodation power measurements The selected designs were tested on a specially constructed test device that simulates accommodation in the eye. The change in power of the IRAL lens was measured in response to the forces exerted on the haptics simulating the process of natural accommodation in the eye. Accommodation in excess of 10D was observed (figure 28). In addition, the increase in refractive power was found to be instantaneous and almost proportional to the force exerted on the haptic. This represents a behavior similar to the natural lens of young humans.

Reference is made to tables 2 to 7 above. The above mathematical construction together with the information contained in the tables allows one skilled in the art to design an accommodation lens of this invention, which is uniquely applicable to the vision needs of a particular patient. "Static power" is a measurement of the power of a lens required to provide correct visual acuity at a distance, such as to drive or observe sporting events. The accommodation provided by a lens of this invention is that the same lens also provides near vision correction, e.g., as required for reading. Therefore, for any given static power determined for a patient, the tables show the radius of curvature that is obtained for any given difference in refractive index (ARI) of liquids I and II (also 32, 34) contained within the Optical camera of the lens body described above. Clearly, the greater the difference in the refractive index (ARI), the greater the liquid interface of the radius and the greater the allowed lens accommodation. The deformation angles of the side wall are shown for various lens arrangements. The "ARI's" of 0.1 and 0.23 that have been used in the tables are to be understood as illustrative, said differences being useful and being within the contemplation of the present invention.

It should be noted that in one embodiment of the present invention, fluids having different refractive indices are used but are miscible. In this structure, the two liquids are separated by a flexible or elastic, optically acceptable membrane, film or divider. The membrane would then define the interface or meniscus between the fluids (e.g., at 16, 16 'in Figure 3, 96 in Figure 13, 36' 36 in Figures 6A-9), and therefore the radius of curvature that determines the degree of accommodation. The membrane that separates the fluids I and II would not be permeable by any fluid, would not be chemically affected by any fluid and would be internally attached to the edge of the optical chamber or lens body to prevent liquids from mixing.

It should be noted that an IRAL of the present invention is a hermetically sealed structure completely. The present IRALs are robust, designed for long-term implantation, which provide many years of almost natural lens accommodation for the patient.

The IRALs of this invention are, in a preferred embodiment, collapsible. In the folding mode of this IRAL, the lens gets a implantation of small incision and other medical benefits provided by folding lOLs. To be collapsible, the materials chosen for the various lens structures must have flexibility or relative rigidity to perform their intended optical function (s) and to provide structural integrity while also allowing the entire structure to be sufficiently soft or flexible to be stored in a folding and unfolding state when inserted in a folded or rolled manner through a small incision during the implantation procedure.

With the above structural and medical functions and mathematical construction in mind, the selection of materials for the various lens structures will be suggested to one skilled in the art. Optically acceptable materials provide the required light transmissivity, depending on their function, and can be implanted in the eye for long periods. The immunological response, biodegradability (or lack of it), and some other physiological factors must all be considered when selecting such materials. The family of acrylate polymers, and polymer chemistry, are suggested for many of the structures of this invention.

The following published patents and patent applications are incorporated herein by reference: US 2004/0181279 US 7,025,783 US 5,443,506 The patents described hereinbefore as paragraphs 0004-0007 are also incorporated herein by reference.

It is to be understood that the embodiments described above constitute only examples of an accommodation lens assembly for implantation in the eye in accordance with the present invention, and that the scope of the present invention fully encompasses other modalities that may be obvious to those skilled in the art. The technique. For example, while the implantation of the lens assembly in humans is described, the assembly clearly can be applicable to other animals. Clearly, any and all possible permutations and / or combinations of different characteristics, as described above, are within the scope of the present invention.

Claims

NOVELTY OF THE INVENTION CLAIMS 1 .- An implantable interfacial refractive ophthalmic lens assembly that adjusts its focal length in response to the changing physiological needs of the user of said lens, the lens comprising a flexible optical and cooperative haptic camera: the optical chamber is defined by opposite circular discs visually transparent, substantially parallel, which are flexibly coupled at their edges and separated to define a closed fluid chamber, the fluid chamber including first and second liquids, liquids having different refractive indices and being immiscible to define a spherical interface or lenticular between them; the haptic being coupled to the edge of the optical chamber and to the fluid chamber so that the application of force to the haptic deforms the fluid chamber and changes the sphericity of the liquid interface; so the focal length of the lens changes in response to the application of force to the haptic to change the focus of the user. 2. - An implantable interfacial refractive ophthalmic lens assembly that adjusts its focal length in response to the changing physiological needs of the user of said lens, the lens comprising a flexible optical and cooperative haptic camera: the optical chamber is defined by circular discs opposite, visually transparent, substantially parallel, which are flexibly coupled at their edges and separated to define a closed fluid chamber, the fluid chamber including first and second liquids having different refractive indices, the liquids being separated by an optically acceptable membrane, the membrane being attached to circular disk edges to define a spherical or lenticular interface between liquids; the haptic being coupled to the edge of the optical chamber and to the fluid chamber so that the application of force to the haptic deforms the fluid chamber and changes the sphericity of the liquid interface; so the focal length of the lens changes in response to the application of force to the haptic to change the focus of the user. 3. - The lens assembly according to claim 2, further characterized in that the lens assembly is foldable. 4. - The lens assembly according to claim 3, further characterized in that the lens is adopted to be implantable in the eye using IOL injectors. 5. - The lens assembly according to claim 2, further characterized in that the difference between the refractive indices of the first and second liquids (ART) is at least about 0.1. 6. - The lens assembly according to claim 2, further characterized in that the difference between refractive indices (ARI) is at least about 0.2. 7. - An implantable interfacial refraction ophthalmic lens assembly that adjusts its focal length in response to the changing physiological needs of the user of said lens, the lens comprising a flexible optical camera and cooperative haptic: the optical chamber is defined by circular discs, visually transparent, substantially parallel, that are flexibly coupled at their edges and separated to define a camera of closed fluid, the fluid chamber including first and second liquids, the liquids having different refractive indexes and being immiscible to define a spherical or lenticular interface between them; the haptic being coupled to the edge of the optical chamber and to the fluid chamber so that the application of force to the haptic deforms the fluid chamber and changes the sphericity of the fluid interface; wherein the haptic defines an internal chamber, the haptic member being in fluid communication with the optical chamber whereby displacement of the haptic subsequently allows the fluid to flow into the optical chamber; so the focal length of the lens changes in response to the application of force to the haptic to change the focus of the user. 8. - The ophthalmic lens according to claim 7, further characterized in that the first and second liquids are separated by a visually transparent elastic membrane. 9. - The ophthalmic lens according to claim 7, further characterized in that the membrane is attached to the edges of the circular discs defining the closed fluid chamber whereby the perimeter of the membrane separates, at least in part, the discs . 10. - The ophthalmic lens according to claim 7, further characterized in that the membrane has a variable thickness.

1. The ophthalmic lens according to claim 7, further characterized in that the membrane is disposed between the circular discs.